You recently appeared on ESPN as a judge for the first World Juggling Federation competition in Las Vegas.

Well, it was actually ESPN2 and I was on for about two seconds. What’s important is that the competition was televised at all. Essentially, the WJF has decided that it wants to style competitive juggling as an extreme sport.

Is juggling an extreme sport?

In Norse sagas, juggling was used as a display of prowess. Soldiers would impress their enemies by juggling knives.

Is that what attracted you?

Well, no. In fact, these days, jugglers tend to be more hippie-like than the general population; and a lot are computer programmers. In high school, being science oriented, I got very interested in whether there was any math or science in juggling. I also liked it because I was a kind of clumsy, not very sporty kid.

So clumsiness is not a liability?

Juggling is like weight lifting. You don’t have to be strong to start lifting weights. If you lift, you get stronger.

There is a mathematics of juggling patterns. People have invented new patterns by coming up with the numbers first. The numbers correspond to heights. If you are juggling three balls in a “cascade,” which is what everybody learns first, the pattern will be “3”—with all balls lobbed up to the same height (3). A harder pattern called the shower might be a “5 1”; the three balls follow a circular route—one hand to the other (1), then up (5), then repeated. Different strings of numbers will be valid or invalid. If two balls crash into each other, the pattern’s not valid.

How did you get involved with organized juggling?

I began going to the International Jugglers’ Association annual conventions when I was an undergraduate in the 1970s at MIT. A thousand jugglers in a room is a pretty amazing sight. Judges are generally chosen from a known group of people who care about juggling and go to competitions. I started out as a timer and then was an assistant judge and then a judge. Ultimately, I helped codify the rules.

Rules?

In the WJF, which was founded in 2000, competitions (like the one on ESPN2) follow a precise, objective scoring system, 100 percent grounded in technical elements. Contestants are athletes—they wear gym clothes. And, as in gymnastics, each technical element is rated on a scale of one to 10. Judges will take off points if you move your foot a little to keep the pattern going. By contrast, the “stage” competitions of the IJA, which was founded in the 1940s by aging vaudevillians, are closer to glorified talent shows. You’ll see a lot more street-performer types, and their scores are based 60 percent on technique, 40 percent on presentation.

What keeps you juggling?

Well, I’m not a performer. There’s a beauty and complexity to juggling, especially to juggling a large number of objects—it’s both tenuous and hypnotic. You can’t juggle six balls and pay attention to anything else. Four times a second, there’s an opportunity to fail.

How many balls can you juggle?

At my best, in my twenties, I could juggle eight balls. Each additional ball is an order of magnitude harder. Four is phenomenally harder than three.

Did you ever juggle anything besides balls?

Oh sure. Juggling torches is not particularly difficult—or knives either. Torches spin just like clubs. And if you accidentally catch the burning part, you just let go very quickly. Your hand might get dirty, but you won’t get burned.

Ever had any mishaps?

It’s easy to hurt yourself a little, it’s hard to hurt yourself a lot. I bruised my toe when I fell off a six-foot unicycle. And you clonk yourself on the head a lot when you’re juggling clubs. That’s going to happen.

You can ride a six-foot unicycle?

Actually, no. I ride a smaller unicycle.

What’s your next trick?

I’ve recently started learning how to walk a slack rope a few inches off the ground. I can stay on it for a couple of seconds. Once I get the hang of it, adding the juggling will be easy.